Question regarding spam wrt general user names

[David Jourard]

Hi,

I hope this question is relevant to this list. If not pls pt me to 
another list.

I have a small server for web hosting and I have been using MailScanner 
for a while to handle the spam assassin and the
virus scanners.  I'm very pleased.

I have spam which is directed to users such as root, mail uucp etc. wrt 
any domain.  Because the e-mail address does not exist it is directed to
root and eventually to me.

Is is possible through mailscanner somehow to reject e-mail from 
root at somedomain1.com, root at somedomain2.com ...,
mail at somedomain1.com , mail at somedomain2.com, ... etc.

Thank-you in advance.

David J.